This contract shall provide testing of chemical agents for their potential to cause teratogenicity and developmental toxicity. The types of chemicals may include, but not be limited to, industrial solvents, plasticizers, food preservatives and colorants, drugs, pesticides, and heavy metals. Generally, this work includes testing of each chemical in two of four species of pregnant laboratory animals, (mice, rats, rabbits, and possibly hamsters) and developing data on the susceptibility of their embryos/fetuses to chemicals during development. The developmental toxicity study shall be conducted in a replicate design with at least 10 animals per dose group/replicate (a replicate can be defined as sperm or plug/positive animals produced within a 2-week period). Additional animals may be included for collection of specimens (e.g., blood, urine, feces, or fetuses) which will be analyzed by the sponsoring agency or, if the contractor has the capability, perform special studies on-site to determine, for example, distribution or pharmacokinetics of the test agent. For the purposes of the description of work, a study is defined as the testing of one chemical on one species or strain in a conventional teratology protocol at a specified period during gestation. Typically, 3 dose groups and a vehicle control shall be called for with at least 20 pregnant animals/group. It is anticipated that the contractor shall be able to conduct up to four studies at a time. A total of forty-six (46) studies are expected to be performed during the contract period of performance. Although most of the effort under Task II shall be devoted to testing chemicals for the potential to produce developmental toxicity, approximately 20% of the effort may be devoted to applied research to test assumptions implicit in developmental toxicity studies or to conduct follow-up toxicity testing.